Center for Innovative Food (CiFOOD), Department of Food Science, Aarhus University, AgroFood Park 48, Aarhus N 8200, Denmark; Aarhus Institute of Advanced Studies (AIAS), Aarhus University, DK-8000 Aarhus, Denmark.
Center for Innovative Food (CiFOOD), Department of Food Science, Aarhus University, AgroFood Park 48, Aarhus N 8200, Denmark.
Carbohydr Polym. 2022 Oct 15;294:119780. doi: 10.1016/j.carbpol.2022.119780. Epub 2022 Jun 27.
Organocatalytic acetylation of pea starch was systematically optimized using tartaric acid as catalyst. The effect of the degree of substitution with alkanoyl (DS) and tartaryl groups (DS) on thermal and moisture resistivity, and film-forming properties was investigated. Pea starch with DS from 0.03 to 2.8 was successfully developed at more efficient reaction rates than acetylated maize starch. Nevertheless, longer reaction time resulted in granule surface roughness, loss of birefringence, hydrolytic degradation, and a DS up to 0.5. Solid-state C NMR and SEC-MALS-RI suggested that tartaryl groups formed crosslinked di-starch tartrate. Acetylation increased the hydrophobicity, degradation temperature (by ~17 %), and glass transition temperature (by up to ~38 %) of pea starch. The use of organocatalytically-acetylated pea starch with DS ≤ 0.39 generated starch-based biofilms with higher tensile and water barrier properties. Nevertheless, at higher DS, the incompatibility between highly acetylated and native pea starches resulted in a heterogenous/microporous structure that worsened film properties.
采用酒石酸作为催化剂，系统优化了豌豆淀粉的有机催化乙酰化反应。考察了取代度（DS）和酒石酰基（DS）对热稳定性、耐湿性和成膜性能的影响。与乙酰化玉米淀粉相比，DS 为 0.03 至 2.8 的豌豆淀粉具有更高的反应速率。然而，较长的反应时间会导致颗粒表面粗糙度增加、双折射消失、水解降解，DS 最高可达 0.5。固态 C NMR 和 SEC-MALS-RI 表明，酒石酰基形成了交联的二淀粉酒石酸酯。乙酰化增加了豌豆淀粉的疏水性、热降解温度（提高约 17%）和玻璃化转变温度（提高最高达 38%）。使用 DS 小于等于 0.39 的有机催化乙酰化豌豆淀粉可以生成具有更高拉伸强度和水阻隔性能的淀粉基生物膜。然而，在更高的 DS 下，高度乙酰化和天然豌豆淀粉之间的不相容性导致了异质/微孔结构，从而使薄膜性能恶化。
